Actives are built by frequency rather than by strength. Run one at a time, ramp it over twelve weeks, keep recovery nights permanently, and judge it at the end of its own response window rather than at week four. The comparative timeline table sets every active against every other.
The retinoid ramp
Week by week frequency, the retinisation window, and the three rules that stop it going wrong.
12 weeks Duration01 night/week Start
Intermediate Level
02
Vitamin C
A protective morning active with a modest effect, a short shelf life and a high rate of pointless purchase.
Morning PositionWeek 08 First check
Intermediate Level
03
Salicylic acid
Oil soluble, so it works inside the pore. Two nights a week, and the reasons not to go higher.
0.5 to 2% Concentration02 nights/week Frequency
Intermediate Level
04
AHA frequency
Surface acids with a fast, visible effect and the shortest path to over exfoliation in this publication.
01 to 02 nights Frequency02 nights min Recovery
Intermediate Level
05
Benzoyl peroxide
The most effective over the counter option for inflammatory spots, used as a short contact wash to make it survivable.
2.5 to 5% Strength02 to 05 min Contact
Intermediate Level
06
Azelaic acid
The active for skin that reacts to everything else, working on redness, marks and spots at once.
10 to 20% StrengthDaily Frequency
Entry Level
07
Niacinamide
A well tolerated supporting ingredient with modest claims, and a long list of things it does not do.
04 to 05% ConcentrationDaily Frequency
Entry Level
08
Active timelines
The comparative table. What responds in weeks, what responds in months, and what never responds.
09 Actives01 week Fastest
Reference Level
09
Purge or reaction
How to tell a retinisation period from a reaction, and the stop rule that decides whether you pause, reset or carry on.
Retinoid ActiveWeek 06 Decision point
All levels Level
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